OtherBrowser-SideExploits.PDF

Lecture 28: Web Security: Cross-Site Scripting and Other Browser-Side Exploits Lecture Notes on “Computer and Network Security” by Avi Kak (kak@) April 18, 2017 11:01pm c 2017 Avinash Kak, Purdue University Goals: • JavaScript for handling cookies in your browser • Server-side cross-site scripting vs. client-side cross-site scripting • Client-side cross-site scripting attacks • Heap spray attacks • The w3af framework for testing web applications CONTENTS Section Title Page 28.1 Cross-Site Scripting — Once Again 3 28.2 JavaScript: Some Quick Highlights 5 28.2.1 Managing Cookies with JavaScript 9 28.2.2 Getting JavaScript to Download 22 Information from a Server 28.3 Exploiting Browser Vulnerabilities 29 28.4 Stealing Cookies with a Cross-Site 31 Scripting Attack 28.5 The Heap Spray Exploit 39 28.6 The w3af Framework for Testing 47 a Web Application for Its Vulnerabilities 2 Computer and Network Security by Avi Kak Lecture 28 28.1: Cross-Site Scripting — Once Again • Earlier in Section 27.3 of Lecture 27 you saw an example of a server-side cross-site scripting attack through server-side in- jection of malicious code. In this section here, I will now give an example of a client-side